The Freshwater Crab Conservation Roundtable and the urgent need for forest recovery

I am spending two days at the River Safari absorbing discussions at The Freshwater Crab Conservation Roundtable. It is fascinating and a relief to see this group assembled to further address the issue of native and endemic freshwater crab conservation in Singapore.

Residing in our rare and highly endangered hill streams, Johora singaporensis is on a precipice, despite our efforts these past few years. So it is time to rope in the help and a motivated bunch now has technical support from a variety of experts, some of whom we first talked about seven years ago!

In 2007, Daniel Ng was an honours student determined to work on a conservation issue. He rejected initial applied ideas Peter Ng and myself suggested. We grappled with suitable topics and the idea of the freshwater crab Johora singaporensis emerged.

We thought it almost academic and a little risky due to low population numbers, still we started Daniel out on a Bukit Gombak stream which ran through Ivan Polunin’s house (Polunin’s stream) and Daniel eventually acquired an expertise over many nights there.

Go sample the streams at Bukit Timah now, we told him, just for the sake of a comparison. It is necessary and we expected it to be routine. Daniel came back with some bad news, typically with just few words, “there are no [Johora singaporensis] crabs there”. We thought he must be mistaken and sampling too gently. So we huge and puffed up Bukit Timah hill with some experienced marine carcinologists, JC Mendoza and Tohru Naruse,but hey drew a blank too.

The realization sunk in that the changes to Bukit Timah we had been concerned about greatly over the years had begun to express itself through the disappearance of its sensitive fauna. The Singapore freshwater crab was just one of many signs.

Quietly over the years, NParks and NUS have advised and worked with MINDEF, PUB, SLA and other agencies to advise about land use in various forests which harbour the crab, protecting the stream ecosystem in which it resides. We have all kept an eye on the sites, alerting NParks over signs and activity, natural and man made which may affect the area. Student projects on other endemic species such as have informed management about status and priorities.

The efforts have become more structured. Darren Yeo, who did his 3rd year Zoology congress (pre-UROPS) project with crustacean study under Peter Ng had returned from his post-doc to set up a well populated invasive species biology and freshwater ecology lab and has now taken lead with these efforts and has initiated a few more student projects. Daniel completed his PhD and returned to conservation research of the crab once again, and is now in Darren’s lab. NParks conjured up the funding to further this. Cai Yixiong in NParks has managed and initiated freshwater stream surveys in our forests, recruited students on stream ecology projects and liaised with various agencies to preempt surprises on the landscape.

We have found a few more sites in addition to the precious few but accelerating changes in forest structure and hydrology have raised the question of captive breeding as an additional strategy in conservation. And Wildlife Reserves Singapore has stepped forward, not just with supplemental funding but a desire for hands on contributions.

And all those people, directly and indirectly relevant to the issue, were assembled in the room yesterday. It included IUCN/SSC specialists experienced in facilitating complex conservation issues who were on hand to help synthesise the diverse input and challenges into an action plan.

When I left for my evening class back at NUS as a vision for this effort was being edited. A humble but lofty goal of endemic crabs flourishing means a healthy ecosystem. Amidst the discussion, Sonja Luz of Wildlife Reserves Singapore reflected on the fact that this was the first species conservation plan for any species in Singapore. Indeed!

The land use, biological, hydrological, law and climate change issues have meant no single one of us in the room could have solved the problem. No less than this Roundtable has been needed all this while. At the biological information is ready to be tapped by all the rest.

I’ve been a cheerleader in this effort for eight yeas now, ever since Daniel’s honours year thesis. It has given me a front row seat to the effort, and the chance to twist and turn through our forests mapping out stream locations on recce’d and observing freshwater crabs in the dark of the night through the glow of headlamps. Watching them in quiet nights bring me back to my first night visit to Bukit Timah Nature Reserve with D H Murphy and the Biological Sciences Society in 1987. Each glimpse is still a fascinating, precious moment.

The forest has changed since my undergraduate years in the late 80’s. You need a permit to step foot in any protected forest patch at night. I stopped night forest walks in the 90s in support of NParks’ biphasic impact-reduction plan – leave the forest free of human presence at night.

But the inadequacy of our forest size, the high proportion of edges, regularly-fogged condominium developments abutting the reserve, pressure of increasing recreational demand, lack of attendant changes in human behaviour, poaching and illegal use incidents, expression of historical impact and our unique problems of forest biology demand new approaches to ensure our unique forest heritage can be passed down to future Singaporeans, as part of our identity.

Well, perhaps not so new. I have heard since a student and more than once, from the likes of Richard Corlett, Subaraj Rajathurai and Peter Ng, somewhat wistfully, about the closing of Bukit Timah Nature Reserve to human traffic – in order to provide relief, restoration and remediation. Is this unreasonable?

These past couple of decades I have lived through upgrading of HDB flats, reconstruction and refurbishment of retail buildings and renovation and regularisation of most NUS blocks. The phenomenally iincreasing Singapore population demands this.

Our forests, ever under siege, face an increasing and diverse pressure. They are irreplaceable and deserve the kind of attention we have unleashed on our urban environment. We have to fix this now.

Read about the conservation strategy for the Singapore freshwater crab here